JavaScript

This is an interesting presentation entitled, JavaScript Must Die, by John Graham-Cumming. Obviously, I disagree with the premise, but he looks at the many security flaws in current JavaScript implementations, which makes this a very useful read.

HTML 5

John Resig also explores the new HTML 5 parsing specification, which ensures that browsers will finally have common rules for how the DOM should be parsed. Hopefully, we will have less need of browsers specific code in the future.

This is a great HTML5 Security cheat sheet that explains what new security risks you should be aware of in HTML 5, especially if you are letting users input HTML.

Frameworks

The jQuery team has released version 1.5. There are a lot of improvements, but much of the release focused on the complete rewrite of the AJAX engine.

An issue show up on twitter recently, where jQuery querySelectorAll queries slowed way down after twitter upgraded from version 1.4.4 to 1.4.4. The jQuery team has since reverted some changes, which affected the performance. You can read more.